The corollary to the Fermi Paradox is the Dark Forest theory, which mostly says everyone is hiding because there are predators in the forest who make a meal, so to speak, of the unwary or careless, but do it in such a way that they are not noticed by other predators: for instance: launching a ‘seed’ from beyond the Ort Cloud which, when it reaches some point in the solar system, unfurl and convert the entire system into a two dimensional object.
David Brin and others resigned from the board of SETI if I recall because they started ‘active SETI’ where they started powerful tight beaming to interesting points in the sky instead of listening. They supposedly had no debate, just started doing it.
Besides aggressive theories like the dark forest theory and ‘the berserker theory’ there could be passive explanations, like once everyone gets so technologically advanced they just fall into a virtual reality hole where reality is simulated perfectly and everyone lives in bliss or something. Or hard as it would be for us to imagine, the desire to explore could be exceedingly rare but sentience and life are not rare.
Freegards